A conveyor belt is known, for example from the publication U.S. Pat. No. 5,547,071. This known conveyor belt is constructed of module rows, each module row comprising one or more modules made of plastic situated side by side in the transverse direction of the conveyor belt. Each module has a set of first aligned spaced fingers extending in a first direction from a module element disposed transversely to the longitudinal direction of the conveyor belt. A set of second aligned spaced fingers extends in the opposite direction from the base element. The second fingers are generally disposed in a staggered position relative to the first fingers. Adjacent module rows engage with each other by means of first fingers of a module and second fingers of an adjacent module etc. In the assembled state the first and second fingers of adjacent modules overlap and are situated side by side. The modules are connected to each other by means of connecting pins extending in the transverse direction of the conveyor belt through transverse apertures in the fingers. In order to make it possible for the conveyor belt to pass through curved conveyance sections of the conveyance path along which it is to travel, the transverse apertures of one of the sets of spaced fingers are elongated holes in the longitudinal direction of the conveyor belt. This makes it possible for the module rows to shift at an angle relative to each other in a bend or other curvature of the conveyance path so that the module rows collapse on the inside of the curve. In the modular conveyor belt disclosed in this publication so-called integral sideplates which are stronger than the other fingers are provided. These sideplates are formed by providing for the two outermost fingers of a set of first fingers and a finger situated between them from the other set of second fingers of an adjacent module to be made of a thicker and heavier design. The object of this construction is to enable the belt to withstand the fill tensile stress to which it is exposed in the longitudinal direction in a bend. This means that separate sideplates on the side edges of the modules are unnecessary, which results in a reduction of the production costs in terms of time.
A conveyor belt is also known from WO 2004/058603 as well as U.S. Pat. No. 5,139,135.
WO 2004/058603 shows a module for a conveyor belt, which comprises on each side a set of spaced fingers with interspaces in between. In the middle part of the module the fingers have a small width and the width of the interspace between those small fingers is correspondingly small. In the side parts of the module the fingers have a large width—measured from the drawings this large width is about 3 times the small width—while the width of the interspaces between those large fingers is correspondingly large. The form and dimensions of the small fingers are essentially the same as the form and dimensions of the small interspaces and the form, while the form and dimensions of the large fingers are essentially the same as the form and dimensions of the large interspaces.
U.S. Pat. No. 5,139,135 shows conveyor belts made of modules. Each module has on each side a set of spaced fingers with interspaces in between. The form and dimensions of the interspaces are essentially the same as the form and dimensions of the fingers. In FIG. 4 prior art and FIG. 6 of U.S. Pat. No. 5,139,135, a dual pitched conveyor belt is shown, i.e. in the inner curve section of the belt, the fingers and interspaces have a smaller pitch as well as a smaller width than in the outer curve section of the belt. This dual pitch facilitates the ability of the belt to turn around a reduced radius.
A disadvantage of known modular conveyor belts produced according to the abovementioned principle is the relatively long run-in length and run-out length of a bend, which according to current guidelines is at least 450 mm irrespective of the belt width, up to twice the width of the conveyor belt. The terms run-in length and run-out length refer to the length of the conveyance path upstream and downstream respectively of a bend or curvature which is needed for the conveyor belt to change from a straight conveyance path section into a curved conveyance path section, and vice versa. The length required for this run-in and run-out is, however, not always available and can entail further unused floor surface.